Vacuum screed



June 3, 1941. N, HELTZEL 2,244,297

VACUUM SCREED Original Fiied Nov. 9, 1956 2 Sheets-Sheet 1 ..I. N. HBLTZB) June 3, 1941. J. N. HELTZEL 2,244,297

VACUUM SCREED Original Filed Nov. 9, 1936 2 Sheets-Sheet 2 J. N. H BLTZ EL,

Extentcd June 3, 1941 UNE'EED STATES PATENT OFFICE ZMMMQ'Z VACUUM SCREW John N. HeltzeLWarren, Ohio Application November 9, 1936, Serial No. 110,016 Renewed January 29, 1940 12 Claims.

This invention relates to road building machines and has for an important object thereof the provision of a machine embodying means whereby the voids in the concrete after the concrete has set will be eliminated.

An object of this invention is to provide a combined surfacing means and a means for withdrawing air and water from the plastic concrete at the time the road surface is being formed.

Another object of this invention is to provide a machine of this type which is so constructed that it will not disturb the plastic material engaging the forms for the roadway and which, at the same time, will compact the material between the side forms and about the reinforcing means usually embedded in the body of the concrete.

A further object of this invention is to provide time, withdrawing air in the plastic material and simultaneously withdrawing free water.

With the foregoing and other objects in view; the invention will be more fully described hereinafter,.and will be more particularly pointed out in the claims appended hereto.

In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views:

Figure 1 is a fragmentary perspective view of a device constructed to an embodiment of this invention mounted on a frame of a plastic material mixing and discharging machine.

Fig. 1-A is a fragmentary view with parts in section showing the modified form 'of vibrating device.

Figure 2 is a fragmentary perspective view of a modified form of this invention.

Figure 3 is a fragmentary perspective view of an improved form construction for the side of the roadway. V

Figure 4 is a fragmentary perspective view of the abutting edges of a roadway constructed with the forms shown in Figure 3.

Figure 5 is a fragmentary perspective view of another type of form for the edge of the roadway.

Figure 6 is a fragmentary perspective view of a modified form of vacuum screed which may be used with the embodiment shown in Figure 1.

Referring to the drawings and first to Figure 1 the numeral id designates generally a frame structure which is associated with a concrete mixing and distributing machine. The frame structure It includes side frame members H which are preferably disposed in an elevated position from the side form members l2 which constitute the form between which the plastic concrete C is poured. A pair of screed members II and I5 are disposed between the side members ll of the frameand are positioned in spaced relation to each other as will be hereinafter described. The screed members It and it are adapted to slidably engage the upper edges of the form members i 2. Universal couplings I5A connect the screeds to machine frame for back and forward screeding, while at the same time permitting of the raising and lowering of the screed members.

The screed members M and i5 are suspended from the frame members H by means ofa chain I3, one end of which is secured to the adjacent ends of the screeds l4 and Hand the remaining portion of the chain i3 is wound about a drum it supported by supporting members l'l secured to the side frame members H. The drum I8 is rotated by means of a lever l8 and a ratchet I s engaged by a pawl 20. The ratchet I 9 issecured to the shaft 2! on which the'drum is fastened and the pawl 28 is secured to the lever 88. There are two of these chains 13 and two drums IS with the other parts associated with the drum IS. The chain i3 is divided at its, lower end as shown in Figure 1 so that a single chain may be used to raise or lower the adjacent ends of the screeds l4 and I5.

Through the use of the flexible supporting members l3 the screeds I4 and I! may be supported in desired relation with respect to the upper edges of the form members l2. The flex-, ible members ll provide-a means whereby the screeds I4 and I! may be supported for lateral movement across the form and in order to eflect lateral movement of the screeds l4 and- I5 .I have provided a screed reciprocating shaft 22 which is adapted to be connected-to a suitable source of power (not shown) and this drive shaft 22 is provided with an eccentric 23 which is engaged by one end of a link 24. -The link 24 at the other end is connected to aboss or bearing 25 carried by the screed member I5. As the shaft 22 is rotated the eccentric or cam 23 will effect lateral movement of the two screeds II and I5. I

A vacuum housing 26 is secured between the two screeds l4 and i5 and holds these two screeds in spaced apart relation so that the screeds will move laterally under the reciprocation of the pitman 24. The housing 26 is preferably shorter in length than the length of the screeds I4 and I5 and is also slightly shorter than the distance between the side forms if. The housing 2 is open on its under side and an air pump 21 secured to a transversely extending beam 28 is connected to the vacuum chamber or housing 2' by means of a flexible tube 29. The details of the pump 2'! are convention nd it-is thought that a further description thereof is unnecessary. Preferably, the hose 29 is connected to the top of the vacuum housing "in the center thereof as shown in the drawings. An additional pitman and eccentric may be mounted on shaft 22 and connected to screed H; or, as shown, the reciprocating movement of screed I! may be transmitted to screed H by the vacuum casing 26 which is secured to both screeds. y

Simultaneous with the lateral reciprocation of the screed members 14 and I! the screed members may be vibrated by means of vibrating elements 30 and 3| secured tothe screeds I4 and I! respectively adjacent their outer ends. These vibrating elements ill and 3| may be electrically operated being connected to a suitable source of electric current supply by means of conductors 32 and 33 respectively. a

As shown-in Figure 1, the screed member I4 is constructed in the form of a channel member having a flat bottom 34 and upstanding walls or flanges and 36. The wall 35 has a pair of forwardly extending vertical wall. members 31 braced by bracing members ll. These wall members 3! form a box or material retaining means to retain the concrete on the forward side of the screed member [4 as the machine moves forwardly.

The frame member I! is moved forwardly on wheels 38 secured to a shaft 4| and the shaft 4lhas a sprocket or drive pulley engaged by a flexible driving member 42 which. is operated by a suitable source of power supply. The forward ends of the frame members II are provided with vertically disposed guide members 43 and wheels '44 are rotatably carried by spindles or brackets 45 secured to the guide members 43. Preferably, these front wheels 44 are of the pneumatic type so that the vibrations of the frame members II will not be communicated to the form members I2. 7 V

A substantially U-shaped frame 48 is disposed between the guide members 43 and is mounted on a shaft or bar 41 which is secured between the vertical legs 48 of the frame 48. Aspring member 48 has oneportion thereof secured as at 50 to a vertical leg of the frame 46 and another portion of the spring structure" is secured to a guide member il which engages in a channel 52 provided in the guide member 0.- An adjusting screw I3 threadably engages the slide 5| so that the entire frame 46 may be vertically adjusted between the rails or form members l2. A plurality of plastic material vibrating members 54 are loosely mounted on the shaft 41 and comprise a sleeve 55 which is loose on the shaft 41 and a plurality pf elongated teeth 58. There are-a number of these material vibrating members 54 mounted on the shaft 41 and the shaft 41 is braced by means of a plurality of depending hangers or bearing members 51 which are secured to the horizontal portion 50 of the frame 40. The ,frame- 48 with the material vibrating members t4, are vibrated by means of a vibratmg element 59 which may be electrically operated and connected by conductors 60 to a suitable source of electric current supply.

The vacuum member 28 may be constructed out of sheet metal or may be constructed out of relatively flexible material and this vacuum member 26 is provided in onegend wall 6! thereof with a liquid discharge connection 62 so that the water drawn up into the housing 28 may be removed by a suitable suction device.

Referring now to Figure 2, there is here shown a screed structure "(r-Ha having a vacuum housing 26a disposed therebetween. The vacuum housing 26a has a flexible hose 29a secured thereto which is connected to a suction device similar to that shown in Figure l. The out-let connection for water, designated 02a, is adapted to have a siphon member 63 secured thereto so that any water in the housing 25a may be siphoned out. If desired the siphon 43 may be supplemented by a pump 64 which extends down through the top of the housing 28a and is provided with a discharge nozzle or connection 88. This pump may be braced by means of bracing members 86.

In Figure 6, there is shown a modified form of screed and vacuum means and in this form there are provided a pair of vacuum housings 81 which are formed integrally with the screed members 88, "and II. A vertically extending wall II is formed on the longitudinal outer edge of the screed member 8 and a vertical wall or flange I2 is formed on the longitudinal edge of the screed member 10. A pair of suction pipes 14 are connectedrt one end to the vacuum housings 61 and are connected at the other end to a suction device similar to that shown in Figure 1.

As shown in Figure 1, the side forms I! are constructed of sheet metal being formed with a top rail I3, a vertical plate 15, and a flanged base plate I6. The vertical wall 15 is preferably provided with a channelled intermediate portion 11 of concavo-convex configuration with the con cave side outermost and preferably, the depth of the channel ll is sufficient to receive wedges II which engage in loops I9 formed by tie rods which are embedded in theconcrete and project through slots provided for that purpose in the channelled portion 11. The convex inner side of the side rail I2 provides a concave channel 88 in the side wall of the concrete body C. As shown in Figure 4, the adjacent block C is adapted to be formed with a tongue 8| which engages in the groove orrkeyway of the block C. The block 0' is adapted to have looped tie members 82 which engage the tie members or loops I! so that two blocks C and C are securely locked together.

In Figure 3, there is disclosed another form of side rail construction and in this form an outer form member Ila: is provided having an upper rail 13aand a vertical wall 150. The vertical wall 16a is secured at its lower end to a channelled base member 16a. A separable keyway forming member 83 is adapted to engage against the inner side of the vertical wall 15a and comprises an elongated plate 84 having a concaveconvex intermediate portion 85 provided with a plurality of spaced apart slots 88 through which the looped portions of the tie members I9 are adapted to engage. Wedges or tapered securin members I8 hold the tie members I! in the slots 86. The lower edge of the plate I4 is provided with a plurality of outwardly extending feet or base members 81 which are adapted to engage beneath the base 16a and thereby hold the plate 85 in upright position and in contacting relation with the inner side of the vertical wall 150. In Figure 5, there is disclosed another form of side rail construction somewhat similar to that disclosedin Figure 3. In this form, however, the outer form member l2b is provided in the vertical wall 75b with a plurality of slots 88 through which the loops of the tie members 18 are adapted to project. An inner keyway forming member 83b comprising a plate 84b having a concavoconvex channel 85b is adapted toengagc against the inner side of the vertical wall 15b andis provided with spaced apart slots 88b through which the tie members 19 project. These slots 85b are adapted to register with the slots 88 so that wedges or -other holding means may be passed through the'projecting loop portion of the tie member E9 on the outerside of thevertical wall 75b. 9

In the use and operation'of the device disclosed in Figure 1, the material is poured into the space between the form members I2 and the frame extensions I I may be disposed on either the forward or rear end of the concrete mixing and distributing machine, depending upon the condition of the road and other conditions which may be encountered. The screeds I4 and I are adjusted relative to the rails I3 by the chains I3 so that after one portion of the lateral reciprocation thereof the screeds I4 and I5 will substantially contact with the rails I3 and adjacent the end of the lateral movement of these screeds in either direction the screeds will be slightly raised thus efiecting a pulling of any water or air in the space between the screeds. which is occupied by the vacuum housing 26. The suction member 21 will beoperated continuously to continuously withdraw air and substantially free water from the plastic concrete and-the water will be retained in the housing 26 from which it may be withdrawn by the means disclosed in Figure 2. Simultaneous with the lateral reciprocation of the screeds I4 and. I5 by means of the shaft 22 and the pitman 24, the screeds may be vibrate by theivibrating elements 30 and 3|.

' At the same time that thescreeds I4 and I5 are reciprocated and vibrated, the frame 46 is vibrated by means of the vibrating member 59 and the teeth 56 of the compacting members 54 will be vertically vibrated within the plastic concrete. The teeth 56 may extend down into the plastic concrete to the depth of the reinforcing rods or may extend below these rods if desired, this being accomplished by the adjusting screw 53 carried by each guide member 43. It has been found that vibrating elements 58 also serve as re-mixing agents and increase the strength of the concrete bythis re-mixing operation simultaneously as these elements are vibrated when j being moved in and out of the plastic mass as the machine moves forward.

The screed construction di closed in Figure 6 will be used with the compacting members" 54 and the screed members here disclosed will be suspended by similar flexible members to those shown in Figure 1.

It is the general practice to vibrate along the side forms by using a portable vibrator. For this operation'Iprovide a vibrating element 90, which is enclosed in the outer casing 9|. There is also an inner casing Slato protect the vibrating mechanism, which may consist of an electric apparatus or a pneumatic hammer, as might be required. There is a suction tube 92, which connects with the space between the casings 9| and the'line 53 would consist of hose to supply the air tgg perate the pneumatic vibrator. Where electric current 'is used, thenthe line 93 would consist of suitable electric wire." In either case suitable valve arrangements 94 are supplied to operate the vibrator, as well as the vacuum apparatus Itv be understood jthat portable)!- brator is moved-manuallyandisinroji'ectedliown into the plastic concrete pat, various. intervals along the side forms to producethe required density of the concrete. Y y I The suction chamber 26 may also be used'with the screed construction'shown without reciproeating the screed construction, and it will be understood that the moist concrete engaging the lower edges of the chamber 26 will act as a sealso that only air and water will enter the chamber 26 which has been drawn 'fromthe plastic concrete. 7 v v Compression plates 5B--A assistjcompacting member, such plates being carried by the teeth or pins 56'near the ends thereof. Instead of the plates, compacting bar members 56B may be provided, or these bar members may be pro; vided in conjunction with the plates 55-;A. The bars 56-3 are carried by pairs of th: pins or teeth 56 so as to rotate therewith arounu the shaft 41'. These plates 56A and the bars 56- B are tamping members-which bear down on the concrete at the same time that the concrete is being internally vibrated. The bars 56-3 area'rranged to bear down on the reinforcing rods and simultaneously vibrate the rods while the pins are internally vibrating the concrete. f

The. sleeves 55 may also carry rotary contact members 56-0 secured to the sleeves by the vibating pins 56, alsohaving other spoke reinforcements if desired. Such members 56-0 will rotate on the reinforcing rods or bars and vibra the same. V I Referring more particularly to Figure l-A,

there here appears a girder reinforcing in a concrete slab and a spiral contact member 55- -D- which contacts the steelreinforcing and'rotates.

progressively as the machinemoves forward. This spiral member is mounted on one of the sleeves on shaft 41.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changesand modifications being restricted only by the scope of the following claims.

What is claimed is: ,1. In a road building machine, spaced scrccds,

a vacuum casing between the screeds and extend ing substantially from one screed to the other screed, means for laterally reciprocating the 'screeds across the road of plastic'concrete, means to withdraw air from the casing whereby to create an area of vacuum between, and extending substantially the full longitudinal distance between, the laterally reciprocating screeds, and means for discharging the water from said casing.

jacent the end of their lateral movements thus effecting a milling of any water or air in the space between the screeds, a vacuum casing secured to the screeds and lying between the same, said casing having an open bottom to subject the area of the concrete between the screeds to the .vacuum action. means to create a condition of vacuum in said casing, and means to relieve the water from the casing.

3. In a road building machine for plastic roads retained by side forms, a plurality of screeds" spaced apart longitudinally of the road and supported upon the side forms for lateral reciprocating motion, means to laterally reciprocate said screeds, a vacuum casing between and secured to said screeds being shorter in length than the screeds and shorter than the distance between the side forms, said vacuum casing being reciprocated laterally with the screeds and having an open bottom portion for subjecting the intervening area of concrete between the screeds to the vacuum action, means for producing a condition of vacuum in said casing, and means for relieving water therefrom.

4. In a road building machine for plastic roads confined by side forms, a screed, means to reciprocate said screed laterally of the road, a vacuum casing secured to said screed and reciprocated therewith, said casing being open at its bottom just above the plastic road material and immediately adjacent said screed for subjecting such material to the action of vacuum, means for creating a condition of vacuum in said casing. and means for withdrawing the water from the casmg. I

5. In a road building roads under construction confined by side forms, a screed, means for laterally reciprocating said screed over the road and across the side forms, means for vibrating said screed as it is reciprocated, a vacuum casing extending oil and secured to move with said screed, said vacuum casing being open at its bottom adjacent an area of the concrete lying beside that being screeded whereby to withdraw the air and water from such concrete, means to produce a condition of machine for concretedistance between the laterally reciprocating screeds.

7. In a road building machine, a screed, a vacuumhood secured thereto. a second screed secured to the hood, and means to apply reciprocating motion to one screed transferred through the hood to the other screed.

8. The hereindescribed method for solidifying plastic concrete of a road under construction, which consists in pouring plastic concrete, moving a surfacing member longitudinally over the plastic mass of concrete while in contact with such concrete, and simultaneously with the surfacing action drawing air and water from the mass of concrete.

9. A device as described comprising a weighted plate portion for resting upon the surface of a plastic road under construction and for compasting and smoothing the same and driving the water and air upwardly from the plastic mass, means behind said plate portion for withdrawing the liberated air and water from the plastic road surface, a second rear plate portion following said means and subjecting the plastic mass to weight and pressure to break down the cell walls and to compact the mass, means for drawing said plate portions and said means along the surface of the roadway in a continuous. operation, and means for subjecting both plate portions to a substantially continuous vibration.

10. A deyice as described comprising a wide and long heavy plate portion resting directly on the surface of the plastic roadway under construction for smoothing and compacting the plastic material and driving the water and air to the surface vacuum means for withdrawin the air and water at the rear edge of said plate portion, a second plate portion wide and long following said vacuum means and being of substantial weight and resting directly on the surface of the plastic material to break down the cell walls and to compact and smooth the plastic mass; means for subjecting both plate portions substantially continuously to vibratory action, and means for drawing both plate portions and said vacuum means along the surface of the plastic material in a continuous operation.

11. In a device for making plastic roads, a carriage movable along, the road,'a plate member being freely'suspended from said carriage and adapted to be directly supported on the plastic road, and vacuum means carried by an intermediate portion of the plate for withdrawing air and water from the plastic concrete.

12. In a device for making roads of plastic material, a carriage movable along the road, a plate member wholly supported from the carriage and adjustable therewith adapted to rest directly on the plastic material, and a vacuum chamber carried by an intermediate part of the plate for withdrawing air and water from the plastic material of the road.

JOHN N. HELTZEL. 

